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Editorial

Full editorial with code solutions is available after submitting a correct solution.

Discussion

tourneysolver 2 hours ago

Great problem. The key insight is using a hash map for O(1) lookups. Once you see that pattern, it becomes straightforward.

codemaster99 5 hours ago

Can also be solved with two pointers if the array is sorted, but the hash map approach is more general and works in O(n).

My Submissions

Status	Language	Runtime	Memory	Time
Accepted	Python	52 ms	14.2 MB	2h ago
Wrong Answer	Python	—	—	3h ago

def twoSum(nums, target):
    # TODO: Implement your solution
    seen = {}
    for i, num in enumerate(nums):
        complement = target - num
        if complement in seen:
            return [seen[complement], i]
        seen[num] = i
    return []

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Test Cases

nums = [2,7,11,15]
target = 9

Output

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